When it comes to sportbike performance I’ve always advocated for lighter weight over higher horsepower. A few recent events have augmented exactly why concentrating on weight reduction is time and money better spent than on increasing power production.

Soon we’ll be posting Sean Alexander’s exclusive first street test of a very special street bike (insert letter and number here). We dyno’d the halo bike to the tune of 193.7 hp at 12,000 rpm and 92.2 lb-ft of torque. Impressive figures, to say the least. Less impressive is the bike’s wet weight of 525 pounds, giving the it a ratio of 2.7 pounds per horsepower.

Comparably, BMW’s S1000RR, the horsepower winner of our forthcoming superbike shootout extravaganza, spun the drum to an equally impressive 182.9 at 13,100 rpm and 79.9 lb-ft at 9600 rpm, giving it a ratio of 2.5 pounds per horsepower. Not a huge disparity in straight line performance between the two but a significant detriment to the special bike’s braking and cornering prowess.

I understand the special bike is not a race bike. The company has another model for that. Having accompanied Alexander during the street test of this secret model motorcycle I can attest to it being a wonderfully balanced street motorcycle with a superbly stable chassis and braking power to match the bike’s insanely fast propulsion. But here’s where things get interesting.

Weighing 170ish, I have, give or take, a 80-pound weight advantage to Sean’s 250ish. Our first top-gear roll-on test with me aboard the BMW and him aboard the other bike was a clear win for the BMW. A second attempt cemented the BMW’s dominance, or so we thought. Swapping bikes – adding his 80 pounds to the BMW and lightening the other bike’s load by 80 pounds with my body weight – gave the top-gear roll-on win to the first-round loser.

80450552Another, more extreme example of weight vs horsepower occurred during our recent superbike shootout, where EiC, Kevin Duke aboard the Honda CBR1000RR SP (150.4 hp at 10,500 rpm and 76.4 lb.-ft at 10,100) could pull-away from BMW S1K mounted Alexander in the middle of Laguna Seca’s front and back straights, even though Alexander was exiting the corners faster and actually closing on Duke at the beginning of each straight. Duke enjoys a 105-pound weight advantage over Alexander but the Honda suffers a whopping 32.5 horsepower deficit to the BMW. With similarly sized riders the S1000RR could simply walk-away from the Honda on the straights.

I know, I get that I’m talking about rider weights, but if you apply what’s so apparent in these examples to reducing the weight of a motorcycle you get my point. By lessening a bike’s weight not only do you achieve better acceleration, but also reap the benefits of a motorcycle that stops and turns better than its heavier, bigger horsepower counterparts.

It seems as though liter-class sportbikes have been stuck in the mid-400 pound weight category for quite some time and I’m unsure the reasons why. Yamaha’s new R1 with an aluminum fuel tank, and magnesium wheels and subframe tipped the scales at 438 pounds wet – a 16-pound reduction from the 454-pound claimed wet weight of the 2014 model. The original 1998 R1 weighed approximately 448 pounds full of fluids. Using it, that’s an average annual weight reduction of about a half-pound per year over 17 years. At least Ducati’s monocoque frame design of the Panigale gets its wet weight down to 427 pounds.

As much as I like the secret bike I keep referring to and all its supercharged badassery, what would really make my hair stand on end would be the introduction of a new superbike producing a mere 150 horsepower but weighing 395 pounds dripping wet for a more affordable price than Honda’s RC213V-S. That’s a perfectly acceptable power to weight ratio of 2.6 pounds per hp, square in the middle of the BMW and special bike. At the current average rate of reducing weight by a half-pound per year it’ll take about nine years to get there. I’d like the OEMs to speed up the process because any advantage gained at their current rate of weight reduction will be negated by my accelerating rate of middle-age weight gain.

  • JMDonald

    Amen brother. Power to weight ratio is paramount. Colin Chapman wrote the book on that philosophy. The ability to stop and turn are the most important attributes of any machine. In my humble opinion of course. I also like the straight line acceleration part of the equation. Well done.

  • Ducati Kid

    Tom,

    Concur with ‘lightness’ being desirable but not at the expense of a worthwhile ride.

    Historic insight?

    Know of many riders felled by a ‘light-in-weight’ while powerful motorcycle, Sport or otherwise, that proved difficult to control during commonplace, daily, street operation.

    Then again, a PORKER wearing tights IS both strange in appearance while functionally lackluster!

    • Reid

      My Duke puts the lie to light weight being difficult to control. I know it being a light bike saved my bacon on many an slippery/rainy occasion.

  • John B.

    For the average (ability not weight) rider, the best way to improve performance is to improve rider skills, and the second best way is to lose weight. Only expert riders who weigh under 150 pounds should worry about shaving a few pounds off a superbike. Dieting is cheaper than carbon fiber and R&D.

    Sport bikes groan when an American rider climbs aboard. Can you imagine the bike’s reaction when an American rider takes a couple laps on a BMW s1000rr and then says the BIKE needs to lose weight? Lol! Yes, lighter is better…. for the bike and for us.

    • FRE000

      I weigh only 143# which is just about ideal for me.

    • Craig Hoffman

      Although it is not high tech and current, as you know from personal experience a bike like a ’98 R1 still packs one hell of a wallop. 150 some odd horsepower in a relatively light and simple bike never really goes out of style does it?

  • Samuel

    RZ350

  • azi

    TL:DR version – because physics

  • Alexander Pityuk

    It is much, much cheaper to add more HP. Bikes already weight too little, further weight reduction has dramatic cost and diminishing returns, as we can clearly see on panigale’s special editions.

  • DickRuble

    Remove all the rider aides (ABS, traction control, etc..) and you may end up with a sub 400lbs bike. You would of course need to bring 50lbs worth of riding skills to compensate.

    • Alexander Pityuk

      And you even may end up flying on it :)

    • Bruce Steever

      ABS might be 2 lbs. and all the other electronics are less than that, combined.

      And trust me, you need all those aids if you plan on using anything in the engine bay of a modern superbike.

      • DickRuble

        I know.. just making the point that things have been added to the R1 since 1998, so it’s kept its weight. More power also needs stronger (heavier) frame, bigger brakes, beefier (heavier) suspension.

        • Bruce Steever

          Yeah, and don’t forget the fun stuff like catalytic converters, larger exhausts, etc.

  • fastfreddie

    Remember reading about the Borile500 on this site.That sounded near perfect

  • CLARITY

    Horsepower will win the top speed segment,regardless of weight. Lightness will always be better for acceleration ,stopping and turning.Weight is a plus for stability at highway speeds.All factor in production bikes.Comparing the H2 and s1000rr is a bit skewed because of the torque difference is compensating weight difference.,not the hp..

    • FRE000

      Torque is not well understood.

      If one bike has 77 ft lbs of torque and another bike weighs the same but has only 70 ft lbs of torque and is geared 10% lower, acceleration will be the same.

  • Craig Hoffman

    New bikes are cool and all, but they cost a fortune. Gimme a clean well cared for used liter bike for peanuts and I am good. 150 plus horsepower never really gets old.

    All these years later, I still vividly remember riding a friend’s then new ’98 R1. What a simple, fast and elegant/pretty bike that was. Something like that with good suspension is really all I need.

  • Buzz

    Sounds like we need to get the Big Pink Thing down to Jenny Craig stat!

  • craig collins

    i rode 2 bultaco metrallas into the ground back in the day. simply wonderful bikes – i could pick one up by myself. light weight is HIGHLY desirable in a motorcycle.